The stone key is one of the two keys found in the ancient section that are used to allow a ladder to descend from a higher-up section. It is found on the ground level on the left after pulling the levers matching the description of the panel.

The chest key is a key that is used to open a chest in the ship. This key is inside of an orb that is collected in the looping traps. To get the key, the player must break the orb using the laser in the basement section.

The lead casting is found on the ground in the tunnel of the root area. It is used for accessing a wisdom gem. It is very similar to the three jewels from Submachine 0 and is most likely a copy of them.

Three keys are found in Submachine 7: The Core, but since they are all called keys, they can only be told apart by color. They are: silver, rusty, and teal. They are used to unlock: the box in the sanctuary that contains the wisdom gem, the room to the right in the upper floor of the Winter Palace, and the box in the Winter Palace that contains a solenoid.

+ = This key, when assembled, serves the same purpose as the circular brass keys. It is found and used in the blue area of the pyramid. It was the first instance in the Submachine series of combining items in the inventory.

This key opens a door acting like a wall. There are two of these found in Sub9. The first is used in the parallel room, and the second is used in a secret area in the pyramid only accessible in layer 8.